Working Draft

Date: Jun. 7, 2001
Link: http://www.w3.org/TR/query-semantics/
Source Author or Organization: W3C

This document defines the formal semantics and core syntax of XQuery, a query language that uses XML structure to express intelligent queries across all structured and semistructured XML data sources.

XQuery is statically typed and uses a type system derived from XML Schema: Formal Description (XSFD). An introductory tutorial demonstrates the features of XQuery, and the way a type is computed for each XQuery expression. The document then delineates the XQuery core syntax and type grammars, the static typing rules (or type-inference rules) and the dynamic typic rules (or value-inference rules).

This specification also covers mapping XQuery declarations to Algebra declarations, and full XQuery grammar to the core syntax. Some misalignments currently exist between the surface grammar (or what the end user will use) and the core syntax. Some syntax and expressions exist in the formal semantics that are not currently available in the surface syntax.

This document replaces XML Query Algebra.